'96 GM Power chip

Can anyone recommend a good one? Or all they all bogus? There are many to choose from......

Also any tips for increasing performance would be helpful. I'm looking for the little things, it runs quite well as is....

Right now, its a low mileage(78K) bone stock '96 GM, with a high dollar dealer tune-up completed today.

Complete dual exhaust(including Cats) will be installed as soon as Friday... Has anyone installed the high flow Cats? Do they cause "check engine light" problems?

Thanks...